Tuesday, May 18, 2010

MONROVIA, Calif. — If NASA's exploration of Mars were summed up in a bumper sticker, it would read: "Follow the water."

Well, we've found the water — ice was discovered by the Phoenix lander in 2008. Now what?

It's time to search again for signs of life, scientists say, something they haven't done since 1976. This time, they want to bring Martian rock and soil samples back to Earth. Here, they could be analyzed for fossilized traces of alien bacteria, or chemical or biological clues that could only be explained by something that was alive.

Such a venture as now outlined would be a three-part act, cost as much as $10 billion and take several years to complete. NASA can't afford it on its own so it recently joined the European Space Agency to map out a shared project.

Space policy experts think the timing is right despite the risks and hefty price tag.

"We're about out of things to do on Mars other than a sample return," said George Washington University space scholar John Logsdon. "It is an extremely expensive undertaking, probably the most expensive robotic mission to Mars and clearly the most complex."